MobileRead Forums - View Single Post - Windows Mobile 5 Signed Applications Snafu

Bob Russell · 11-15-2005, 02:33 PM

We recently reported that the way Windows Mobile 5.0 handles signed applications meant a workaround for ozVGA was necessary to run in VGA mode.

But it seems that this is a more general problem with Windows Mobile 5.0. As I understand it, the OS requires all applications to be digitally signed. On the surface this is a way to guarantee compatibility and safety of the program.

Both the application and the MUI (Multi User Interface) files need to be signed. The MUI files are used to provide things like multiple language support. This would not seem to be an issue because when an unsigned application is launched, you are asked if you want to run the unsigned application and consider it "trusted." That would be fine except for the MUI files when the "security prompt" feature is enabled.

Then when the application is not signed, even if you give it permission to run the application, it can't see the necessary MUI files because they are also not signed. But now you don't have another prompt to accept them, so the program will not operate as expected.

Basically, this forces applications (even freeware apps) to go through an expensive signing process. If they don't, then they get the security message prompt, or if they have MUI files they don't work at all.

This is all a bit beyond my technical understanding, so if you want the full scoop, be sure to check out the two part article by Frank Garcia at PocketNow...
Windows Mobile 5.0 Snafu (Part One)
Windows Mobile 5.0 Snafu (Part Two)

11-15-2005, 02:33 PM	#1
Bob Russell Recovering Gadget Addict Posts: 5,381 Karma: 676161 Join Date: May 2004 Location: Pittsburgh, PA Device: iPad	Windows Mobile 5 Signed Applications Snafu We recently reported that the way Windows Mobile 5.0 handles signed applications meant a workaround for ozVGA was necessary to run in VGA mode. But it seems that this is a more general problem with Windows Mobile 5.0. As I understand it, the OS requires all applications to be digitally signed. On the surface this is a way to guarantee compatibility and safety of the program. Both the application and the MUI (Multi User Interface) files need to be signed. The MUI files are used to provide things like multiple language support. This would not seem to be an issue because when an unsigned application is launched, you are asked if you want to run the unsigned application and consider it "trusted." That would be fine except for the MUI files when the "security prompt" feature is enabled. Then when the application is not signed, even if you give it permission to run the application, it can't see the necessary MUI files because they are also not signed. But now you don't have another prompt to accept them, so the program will not operate as expected. Basically, this forces applications (even freeware apps) to go through an expensive signing process. If they don't, then they get the security message prompt, or if they have MUI files they don't work at all. This is all a bit beyond my technical understanding, so if you want the full scoop, be sure to check out the two part article by Frank Garcia at PocketNow... Windows Mobile 5.0 Snafu (Part One) Windows Mobile 5.0 Snafu (Part Two)